Java tutorial
/* * Copyright (c) 1998, 2015, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.swing.tree; import javax.swing.*; import javax.swing.border.*; import javax.swing.event.*; import javax.swing.plaf.FontUIResource; import java.awt.*; import java.awt.event.*; import java.beans.BeanProperty; import java.util.EventObject; /** * A <code>TreeCellEditor</code>. You need to supply an * instance of <code>DefaultTreeCellRenderer</code> * so that the icons can be obtained. You can optionally supply * a <code>TreeCellEditor</code> that will be layed out according * to the icon in the <code>DefaultTreeCellRenderer</code>. * If you do not supply a <code>TreeCellEditor</code>, * a <code>TextField</code> will be used. Editing is started * on a triple mouse click, or after a click, pause, click and * a delay of 1200 milliseconds. *<p> * <strong>Warning:</strong> * Serialized objects of this class will not be compatible with * future Swing releases. The current serialization support is * appropriate for short term storage or RMI between applications running * the same version of Swing. As of 1.4, support for long term storage * of all JavaBeans™ * has been added to the <code>java.beans</code> package. * Please see {@link java.beans.XMLEncoder}. * * @see javax.swing.JTree * * @author Scott Violet */ public class DefaultTreeCellEditor implements ActionListener, TreeCellEditor, TreeSelectionListener { /** Editor handling the editing. */ protected TreeCellEditor realEditor; /** Renderer, used to get border and offsets from. */ protected DefaultTreeCellRenderer renderer; /** Editing container, will contain the <code>editorComponent</code>. */ protected Container editingContainer; /** * Component used in editing, obtained from the * <code>editingContainer</code>. */ protected transient Component editingComponent; /** * As of Java 2 platform v1.4 this field should no longer be used. If * you wish to provide similar behavior you should directly override * <code>isCellEditable</code>. */ protected boolean canEdit; /** * Used in editing. Indicates x position to place * <code>editingComponent</code>. */ protected transient int offset; /** <code>JTree</code> instance listening too. */ protected transient JTree tree; /** Last path that was selected. */ protected transient TreePath lastPath; /** Used before starting the editing session. */ protected transient Timer timer; /** * Row that was last passed into * <code>getTreeCellEditorComponent</code>. */ protected transient int lastRow; /** True if the border selection color should be drawn. */ protected Color borderSelectionColor; /** Icon to use when editing. */ protected transient Icon editingIcon; /** * Font to paint with, <code>null</code> indicates * font of renderer is to be used. */ protected Font font; /** * Constructs a <code>DefaultTreeCellEditor</code> * object for a JTree using the specified renderer and * a default editor. (Use this constructor for normal editing.) * * @param tree a <code>JTree</code> object * @param renderer a <code>DefaultTreeCellRenderer</code> object */ public DefaultTreeCellEditor(JTree tree, DefaultTreeCellRenderer renderer) { this(tree, renderer, null); } /** * Constructs a <code>DefaultTreeCellEditor</code> * object for a <code>JTree</code> using the * specified renderer and the specified editor. (Use this constructor * for specialized editing.) * * @param tree a <code>JTree</code> object * @param renderer a <code>DefaultTreeCellRenderer</code> object * @param editor a <code>TreeCellEditor</code> object */ public DefaultTreeCellEditor(JTree tree, DefaultTreeCellRenderer renderer, TreeCellEditor editor) { this.renderer = renderer; realEditor = editor; if (realEditor == null) realEditor = createTreeCellEditor(); editingContainer = createContainer(); setTree(tree); setBorderSelectionColor(UIManager.getColor("Tree.editorBorderSelectionColor")); } /** * Sets the color to use for the border. * @param newColor the new border color */ public void setBorderSelectionColor(Color newColor) { borderSelectionColor = newColor; } /** * Returns the color the border is drawn. * @return the border selection color */ public Color getBorderSelectionColor() { return borderSelectionColor; } /** * Sets the font to edit with. <code>null</code> indicates * the renderers font should be used. This will NOT * override any font you have set in the editor * the receiver was instantiated with. If <code>null</code> * for an editor was passed in a default editor will be * created that will pick up this font. * * @param font the editing <code>Font</code> * @see #getFont */ public void setFont(Font font) { this.font = font; } /** * Gets the font used for editing. * * @return the editing <code>Font</code> * @see #setFont */ public Font getFont() { return font; } // // TreeCellEditor // /** * Configures the editor. Passed onto the <code>realEditor</code>. */ public Component getTreeCellEditorComponent(JTree tree, Object value, boolean isSelected, boolean expanded, boolean leaf, int row) { setTree(tree); lastRow = row; determineOffset(tree, value, isSelected, expanded, leaf, row); if (editingComponent != null) { editingContainer.remove(editingComponent); } editingComponent = realEditor.getTreeCellEditorComponent(tree, value, isSelected, expanded, leaf, row); // this is kept for backwards compatibility but isn't really needed // with the current BasicTreeUI implementation. TreePath newPath = tree.getPathForRow(row); canEdit = (lastPath != null && newPath != null && lastPath.equals(newPath)); Font font = getFont(); if (font == null) { if (renderer != null) font = renderer.getFont(); if (font == null) font = tree.getFont(); } editingContainer.setFont(font); prepareForEditing(); return editingContainer; } /** * Returns the value currently being edited. * @return the value currently being edited */ public Object getCellEditorValue() { return realEditor.getCellEditorValue(); } /** * If the <code>realEditor</code> returns true to this * message, <code>prepareForEditing</code> * is messaged and true is returned. */ public boolean isCellEditable(EventObject event) { boolean retValue = false; boolean editable = false; if (event != null) { if (event.getSource() instanceof JTree) { setTree((JTree) event.getSource()); if (event instanceof MouseEvent) { TreePath path = tree.getPathForLocation(((MouseEvent) event).getX(), ((MouseEvent) event).getY()); editable = (lastPath != null && path != null && lastPath.equals(path)); if (path != null) { lastRow = tree.getRowForPath(path); Object value = path.getLastPathComponent(); boolean isSelected = tree.isRowSelected(lastRow); boolean expanded = tree.isExpanded(path); TreeModel treeModel = tree.getModel(); boolean leaf = treeModel.isLeaf(value); determineOffset(tree, value, isSelected, expanded, leaf, lastRow); } } } } if (!realEditor.isCellEditable(event)) return false; if (canEditImmediately(event)) retValue = true; else if (editable && shouldStartEditingTimer(event)) { startEditingTimer(); } else if (timer != null && timer.isRunning()) timer.stop(); if (retValue) prepareForEditing(); return retValue; } /** * Messages the <code>realEditor</code> for the return value. */ public boolean shouldSelectCell(EventObject event) { return realEditor.shouldSelectCell(event); } /** * If the <code>realEditor</code> will allow editing to stop, * the <code>realEditor</code> is removed and true is returned, * otherwise false is returned. */ public boolean stopCellEditing() { if (realEditor.stopCellEditing()) { cleanupAfterEditing(); return true; } return false; } /** * Messages <code>cancelCellEditing</code> to the * <code>realEditor</code> and removes it from this instance. */ public void cancelCellEditing() { realEditor.cancelCellEditing(); cleanupAfterEditing(); } /** * Adds the <code>CellEditorListener</code>. * @param l the listener to be added */ public void addCellEditorListener(CellEditorListener l) { realEditor.addCellEditorListener(l); } /** * Removes the previously added <code>CellEditorListener</code>. * @param l the listener to be removed */ public void removeCellEditorListener(CellEditorListener l) { realEditor.removeCellEditorListener(l); } /** * Returns an array of all the <code>CellEditorListener</code>s added * to this DefaultTreeCellEditor with addCellEditorListener(). * * @return all of the <code>CellEditorListener</code>s added or an empty * array if no listeners have been added * @since 1.4 */ public CellEditorListener[] getCellEditorListeners() { return ((DefaultCellEditor) realEditor).getCellEditorListeners(); } // // TreeSelectionListener // /** * Resets <code>lastPath</code>. */ public void valueChanged(TreeSelectionEvent e) { if (tree != null) { if (tree.getSelectionCount() == 1) lastPath = tree.getSelectionPath(); else lastPath = null; } if (timer != null) { timer.stop(); } } // // ActionListener (for Timer). // /** * Messaged when the timer fires, this will start the editing * session. */ public void actionPerformed(ActionEvent e) { if (tree != null && lastPath != null) { tree.startEditingAtPath(lastPath); } } // // Local methods // /** * Sets the tree currently editing for. This is needed to add * a selection listener. * @param newTree the new tree to be edited */ protected void setTree(JTree newTree) { if (tree != newTree) { if (tree != null) tree.removeTreeSelectionListener(this); tree = newTree; if (tree != null) tree.addTreeSelectionListener(this); if (timer != null) { timer.stop(); } } } /** * Returns true if <code>event</code> is a <code>MouseEvent</code> * and the click count is 1. * * @param event the event being studied * @return whether {@code event} should starts the editing timer */ protected boolean shouldStartEditingTimer(EventObject event) { if ((event instanceof MouseEvent) && SwingUtilities.isLeftMouseButton((MouseEvent) event)) { MouseEvent me = (MouseEvent) event; return (me.getClickCount() == 1 && inHitRegion(me.getX(), me.getY())); } return false; } /** * Starts the editing timer. */ protected void startEditingTimer() { if (timer == null) { timer = new Timer(1200, this); timer.setRepeats(false); } timer.start(); } /** * Returns true if <code>event</code> is <code>null</code>, * or it is a <code>MouseEvent</code> with a click count > 2 * and <code>inHitRegion</code> returns true. * * @param event the event being studied * @return whether editing can be started for the given {@code event} */ protected boolean canEditImmediately(EventObject event) { if ((event instanceof MouseEvent) && SwingUtilities.isLeftMouseButton((MouseEvent) event)) { MouseEvent me = (MouseEvent) event; return ((me.getClickCount() > 2) && inHitRegion(me.getX(), me.getY())); } return (event == null); } /** * Returns true if the passed in location is a valid mouse location * to start editing from. This is implemented to return false if * <code>x</code> is <= the width of the icon and icon gap displayed * by the renderer. In other words this returns true if the user * clicks over the text part displayed by the renderer, and false * otherwise. * @param x the x-coordinate of the point * @param y the y-coordinate of the point * @return true if the passed in location is a valid mouse location */ protected boolean inHitRegion(int x, int y) { if (lastRow != -1 && tree != null) { Rectangle bounds = tree.getRowBounds(lastRow); ComponentOrientation treeOrientation = tree.getComponentOrientation(); if (treeOrientation.isLeftToRight()) { if (bounds != null && x <= (bounds.x + offset) && offset < (bounds.width - 5)) { return false; } } else if (bounds != null && (x >= (bounds.x + bounds.width - offset + 5) || x <= (bounds.x + 5)) && offset < (bounds.width - 5)) { return false; } } return true; } /** * Determine the offset. * @param tree a <code>JTree</code> object * @param value a value * @param isSelected selection status * @param expanded expansion status * @param leaf leaf status * @param row current row */ protected void determineOffset(JTree tree, Object value, boolean isSelected, boolean expanded, boolean leaf, int row) { if (renderer != null) { if (leaf) editingIcon = renderer.getLeafIcon(); else if (expanded) editingIcon = renderer.getOpenIcon(); else editingIcon = renderer.getClosedIcon(); if (editingIcon != null) offset = renderer.getIconTextGap() + editingIcon.getIconWidth(); else offset = renderer.getIconTextGap(); } else { editingIcon = null; offset = 0; } } /** * Invoked just before editing is to start. Will add the * <code>editingComponent</code> to the * <code>editingContainer</code>. */ protected void prepareForEditing() { if (editingComponent != null) { editingContainer.add(editingComponent); } } /** * Creates the container to manage placement of * <code>editingComponent</code>. * * @return new Container object */ protected Container createContainer() { return new EditorContainer(); } /** * This is invoked if a <code>TreeCellEditor</code> * is not supplied in the constructor. * It returns a <code>TextField</code> editor. * @return a new <code>TextField</code> editor */ protected TreeCellEditor createTreeCellEditor() { Border aBorder = UIManager.getBorder("Tree.editorBorder"); @SuppressWarnings("serial") // Safe: outer class is non-serializable DefaultCellEditor editor = new DefaultCellEditor(new DefaultTextField(aBorder)) { public boolean shouldSelectCell(EventObject event) { boolean retValue = super.shouldSelectCell(event); return retValue; } }; // One click to edit. editor.setClickCountToStart(1); return editor; } /** * Cleans up any state after editing has completed. Removes the * <code>editingComponent</code> the <code>editingContainer</code>. */ private void cleanupAfterEditing() { if (editingComponent != null) { editingContainer.remove(editingComponent); } editingComponent = null; } /** * <code>TextField</code> used when no editor is supplied. * This textfield locks into the border it is constructed with. * It also prefers its parents font over its font. And if the * renderer is not <code>null</code> and no font * has been specified the preferred height is that of the renderer. */ @SuppressWarnings("serial") // Safe: outer class is non-serializable public class DefaultTextField extends JTextField { /** Border to use. */ protected Border border; /** * Constructs a * <code>DefaultTreeCellEditor.DefaultTextField</code> object. * * @param border a <code>Border</code> object * @since 1.4 */ public DefaultTextField(Border border) { setBorder(border); } /** * Sets the border of this component.<p> * This is a bound property. * * @param border the border to be rendered for this component * @see Border * @see CompoundBorder */ @BeanProperty(preferred = true, visualUpdate = true, description = "The component's border.") public void setBorder(Border border) { super.setBorder(border); this.border = border; } /** * Overrides <code>JComponent.getBorder</code> to * returns the current border. */ public Border getBorder() { return border; } // implements java.awt.MenuContainer public Font getFont() { Font font = super.getFont(); // Prefer the parent containers font if our font is a // FontUIResource if (font instanceof FontUIResource) { Container parent = getParent(); if (parent != null && parent.getFont() != null) font = parent.getFont(); } return font; } /** * Overrides <code>JTextField.getPreferredSize</code> to * return the preferred size based on current font, if set, * or else use renderer's font. * @return a <code>Dimension</code> object containing * the preferred size */ public Dimension getPreferredSize() { Dimension size = super.getPreferredSize(); // If not font has been set, prefer the renderers height. if (renderer != null && DefaultTreeCellEditor.this.getFont() == null) { Dimension rSize = renderer.getPreferredSize(); size.height = rSize.height; } return size; } } /** * Container responsible for placing the <code>editingComponent</code>. */ @SuppressWarnings("serial") // Safe: outer class is non-serializable public class EditorContainer extends Container { /** * Constructs an <code>EditorContainer</code> object. */ public EditorContainer() { setLayout(null); } // This should not be used. It will be removed when new API is // allowed. /** * Do not use. */ public void EditorContainer() { setLayout(null); } /** * Overrides <code>Container.paint</code> to paint the node's * icon and use the selection color for the background. */ public void paint(Graphics g) { int width = getWidth(); int height = getHeight(); // Then the icon. if (editingIcon != null) { int yLoc = calculateIconY(editingIcon); if (getComponentOrientation().isLeftToRight()) { editingIcon.paintIcon(this, g, 0, yLoc); } else { editingIcon.paintIcon(this, g, width - editingIcon.getIconWidth(), yLoc); } } // Border selection color Color background = getBorderSelectionColor(); if (background != null) { g.setColor(background); g.drawRect(0, 0, width - 1, height - 1); } super.paint(g); } /** * Lays out this <code>Container</code>. If editing, * the editor will be placed at * <code>offset</code> in the x direction and 0 for y. */ public void doLayout() { if (editingComponent != null) { int width = getWidth(); int height = getHeight(); if (getComponentOrientation().isLeftToRight()) { editingComponent.setBounds(offset, 0, width - offset, height); } else { editingComponent.setBounds(0, 0, width - offset, height); } } } /** * Calculate the y location for the icon. */ private int calculateIconY(Icon icon) { // To make sure the icon position matches that of the // renderer, use the same algorithm as JLabel // (SwingUtilities.layoutCompoundLabel). int iconHeight = icon.getIconHeight(); int textHeight = editingComponent.getFontMetrics(editingComponent.getFont()).getHeight(); int textY = iconHeight / 2 - textHeight / 2; int totalY = Math.min(0, textY); int totalHeight = Math.max(iconHeight, textY + textHeight) - totalY; return getHeight() / 2 - (totalY + (totalHeight / 2)); } /** * Returns the preferred size for the <code>Container</code>. * This will be at least preferred size of the editor plus * <code>offset</code>. * @return a <code>Dimension</code> containing the preferred * size for the <code>Container</code>; if * <code>editingComponent</code> is <code>null</code> the * <code>Dimension</code> returned is 0, 0 */ public Dimension getPreferredSize() { if (editingComponent != null) { Dimension pSize = editingComponent.getPreferredSize(); pSize.width += offset + 5; Dimension rSize = (renderer != null) ? renderer.getPreferredSize() : null; if (rSize != null) pSize.height = Math.max(pSize.height, rSize.height); if (editingIcon != null) pSize.height = Math.max(pSize.height, editingIcon.getIconHeight()); // Make sure width is at least 100. pSize.width = Math.max(pSize.width, 100); return pSize; } return new Dimension(0, 0); } } }